A few rules for everyone regardless of how you’re dressing:
Your clothes don’t match, they co-ordinate.
With a polo or sport shirt, never button the top button unless you’re wearing a tie. It’s not edgy, it’s not “nerdy chic”, it just makes you look like you don’t know what you’re doing.
When wearing a suit, NEVER button the bottom button. It’s there to act as a fulcrum for the eye and should line up with your waistband. Buttoning the bottom button just makes you look like you’ve never worn a suit before and therefore aren’t mature or successful enough to know how.
If you’re wearing a tie you’re wearing a jacket, vest, or sweater. You know who wears a shirt and tie without anything over it? Waiters at TGI Friday’s.
Belts or suspenders are required unless your pants have side adjusters (even then you can still wear suspenders).
Belts should match your shoes (or co-ordinate in the case of a surcingle belt).
Suspenders or a belt – never both.